The closest I could get was xenophile. Also, optimistic would be a close second and I say that because I don't think that optimistic is a better description than xenophile because xenophile actually includes love.
Omniphile: omni = every; -phile = love. Xeno- = foreign things, so xenophile means lover of foreign things, not lover of everything.
Besides the already-offered neologism omniphile, consider Pollyanna:
One who is persistently cheerful and optimistic, even when given cause not to be so. [eg] You call her an optimist, but I call her an obnoxious Pollyanna.
My guess would be philomania (phile means 'love', for example, my middle name is Philip, which means lover of horses). Omniphile is someone who wants to have intercourse with everyone/thing.