If I have multiple cyber archfiends on the field during my draw phase how would that play out.

UDE sez
CYBER ARCHFIEND

If this card is face-down during the End Phase, it is not destroyed by its effect.

If you have multiple “Cyber Archfiends” on the field during the Draw Phase, their effects form a chain.

What I don't get is how would the chain resolve? Would I get to draw for all of the archfiends or just for the one?

Yes you would draw for all 3, the chain "formation" consists in how you as the controller would wish to resolve the effects, meaning that because you are the controller of all 3, you would choose which CA's effect you would put on the chain first and last.

Basically, you decide which one to activate first, then which one to chain next, then which one to chain next and then, depending on which one's are in which order, that is how they will be resolved in the chain.