What makes living organisms to divers from one another?

I think you mean what makes living organisms so diverse from each other.

The answer: Adaptation. The environment. It's natural predators, it's food supply, what it has to do to get its food supply and other necessitites of life, etc. It's a combination of all these things that shape them.

Consider bacteria living n a hot vent. Consider fish living at depths that see no sunlight at all. Consider the various shapes of people in the world.