Although it is permissible to cook on Yom Tov, this heter is limited to cooking for other Jews. Because of this prohibition, Chazal were concerned that if one had non Jews as guests, he would cook extra for them. They therefore disallowed inviting non jews on Yom Tov, SA, OC 512:1.(However, they allowed them on Shabbos, see Tur OC: 325). The law is that a Jew who openly violates the Sabbath would also be prohibited to cook for, so he would also be included in the prohibition against inviting gentiles. What is the rationale for the common practice of inviting irreligious jews for the Seder and other Yom Tov meals. Is it permissible for Kiruv purposes? Is it always permissible? Is there any heter to actually cook food for him? Is this a rabbinic or biblical prohibition? Can one at least do chazarah for him?
This article details multiple viewpoints on the issue. I am excerpting the end / author's conclusion. Readers can agree or disagree, or better, follow M.Y.'s adage of consulting their Rav:
Common practice among our community is to host non-observant relatives for Yom Tov. Moreover, it is common practice for observant Jewish hotel owners to host and feed Jews who are obviously non-observant. Outreach professionals routinely invite non-observant Jews for Yom Tov, especially for the Seder. People either rely on the opinions that this prohibition does not apply to non-observant Jews or that contemporary non-observant Jews are regarded as Tinokot SheNishbeh’u. It is certainly preferable in such a situation to cook all the Yom Tov food in advance in order to eliminate concern for violating a Torah level prohibition. In any event, the Halacha (Mishnah Berurah 495:5) prefers preparing food before Yom Tov so as not to be preoccupied with food preparation during the holiday.
Rav Shlomo Zalman Auerbach (ad. loc.) laments the inability to properly observe this Halacha in today’s circumstances. Nonetheless, we should aspire to create highly joyful and spiritual Yom Tov atmospheres in our homes that will inspire non-observant Yom Tov guests to return to a life of Torah observance.
It is ironic that we rely on the opinions that contemporary non-observant Jews are compared to a Tinok SheNishbah in regard to inviting them for Yom Tov. However, in many circumstances we rely on Rav Moshe Feinstein’s opinion that today’s non-observant Jews are not classified as Tinok SheNishbah, and are considered to be invalid witnesses. These circumstances include situations regarding a child of a woman’s second marriage who did not receive a proper Get from her first husband. In such cases, we embrace Rav Moshe’s opinion that the child is not a Mamzeir (illegitimate) if all witnesses to the mother’s first marriage were non-observant. (For further discussion of this issue, see Gray Matter: Volume One pages 83-92.) While there are ways to resolve this inconsistency, it highlights the fact that Rav Moshe’s ruling should be relied upon only if no other options exist. We should all make efforts to ensure that civilly divorced non-observant Jews should receive a proper Get even if they were married in a non-Orthodox ceremony where all witnesses were non-observant Jews. Our discussion raises the very distinct possibility that non-observant Jews are not necessarily disqualified from serving as witnesses, since they may be regarded as Tinokot SheNishbe’u.