Praise be to Allah.
Allah, may He be exalted, has commanded His slaves to cooperate in righteousness and piety, and has forbidden them to cooperate in sin and transgression as He, may He be exalted, says (interpretation of the meaning):
“And cooperate in righteousness and piety, but do not cooperate in sin and aggression. And fear Allah; indeed, Allah is severe in penalty”
Undoubtedly, breaking the fast during the day in Ramadan with no excuse is a major sin and transgression, and failing to respect the sanctity of this month reflects corruption and sin in the heart.
It makes no difference whether the one who breaks the fast in Ramadan is a Muslim or non-Muslim, because the most correct view among the majority of scholars of usool is that the minor issues of sharee‘ah are also addressed to the disbelievers; they are required to follow them and will be brought to account for not doing so, in addition to their being brought to account for disbelieving in Allah, may He be exalted.
Based on that, it is not permissible to distribute sweets or any other kind of food or drink to visitors during the day in Ramadan, if it is known that they will eat them during the day.
Instead of that, you could distribute some other kind of gift, or perfume, or useful books, and so on, or you could distribute sweets at night, if you think that there is a religious benefit in continuing with this event and distribution of gifts, and that it will soften the hearts of your visitors to Islam.
And Allah knows best.