Staff rotation?
2 and 5 off cooldown with auto attacks in between, always on fire unless something specific is needed.
So there’s no reason to go into Air, Earth, and Water?
There isn’t “no reason” but staying in fire is generally the highest dps because lava font does so much damage and has a fairly low cooldown.
You can swap to water for heals and a chill; Air for swiftness, blind, stun, and a lightning field; Earth for immob, reflect, and a blast finisher. Once you have tempest, overload earth is also a 20 second group protection skill, which is situationally useful. But these are generally utility applications, and if you just want to kill whatever you’re against the fastest you should stay in fire, so that is the dps rotation you asked for.
Once you start filling out other traitlines, there is stuff you can do like swap to air for extra crit chance while you use a conjured weapon and glyph of storms, and then swap back to fire when the conjure is used up.