I'm fairly certain that we've had this topic posted multiple times...for both Alien and Predator genders. According to the books, there are female predators, but they are somewhat like homemakers, though they are much larger and stronger than male preds. So yes, they would be much like the Aztecs. This, however, is not canon.
According to the sketches made by Mr. Giger, the creator of the Xenomorph, Aliens have both male and female genders. Drones have differing genders, though they are obviously unable to reproduce, either through pheromone suppression or some form of sterility.
The queen is either female or capable of a-sexual reproduction, this we do not know, though I believe that the Warrior xenomorphs, which are most likely male in gender, produce an alpha male of the strongest physique and build to mate with the queen. The alpha warrior may be the closest thing to a "king" alien that we will ever see.
This would mean that the Xenomorph caste system is divided as follows, through forms of metamorphosis and aging:
Drone (Female) -> Queen
Drone (Male) -> Warrior -> Alpha

"If anything in this life is certain, if history has taught us anything, it is that you can kill anyone." - Michael Corleone