Yes, it's big enough.
Most people say that you need a 2x2x3' cage for an adult female, 2x2x4 for a male.
But then I've heard 2 or three places that a decade or so ago (I can't remember all the details) that most breeders used 2x2x2 for adults successfully (maybe even smaller!) without the adults being stressed.
I would ALWAYS go for the bigger cage. An adult human could live in a room that's 6'x6'x6' easily, but we'd go nuts! Even with a 15x15x15' room, if that's all we had we'd likely still go nuts without tons of stuff to do within it.... In the same way, a cham needs space to do what he needs to do.
A cham needs to thermoregulate - that means enough space to have the mid-70's in one part of the tank and 90's in another. Plus hiding space, plus room for feeders and water.
your cage will work until the cham is likely 6 months old - maybe less, maybe a touch more. But that's only 3-4 months of you owning it. Most pet stores have babies that are 2-3 months old. One I know of has neonates about 3-4 weeks old, tho I wouldn't buy one at that age if it were anything more than $20 (so likely to die from stress). So 5 months if you're lucky - that's how long the cage will be used.
Or you can find a smaller species that you can provide proper temps and humidity for, that can live in such a cage for it's whole life. Veileds are about the easiest chams, tho.
Good luck!