I'm an alright Emperor player... too busy doing all the other competitions on here to really try my luck with Immortal - I don't think I've ever tried Deity since being too scared from Civ IV!!!
I want to say, Religion, Deserts, Petra, Science, Diplomacy win... but do you even have a reasonable chance for that in Deity? What I've read is it's rare to ever get your own religion, and beelining to Petra and trying to build before t80 is going to really slow you down on the science (I suspect? I'm not *that* good of a player to know these things confidently in advance). If this was do-able I'd want to settle on the Plains 1L, get the most of desert & petra and I like fast growth because it gives me more hammers in a bit rather than now.
Alternatively, going for Conquest is the go... but do you really have a chance of wiping out most capitals with Camel Archers? If Deity combat is that much harder and it turns into a modern tech warfare game then surely you've lost your chance to get there first in science?