Emergency!!

I own two baby bearded dragons. My friend came to visit and fell in love with them so I took her to buy her own. Today I find out that the baby's leg was broken while he was in her care. The leg is completely snapped and the bones are showing. I convinced her to let me buy it off of her because she was going to exchange it at the pet store.
I get my paycheck on Friday so I will take him to the vet but until then what can I do for the poor thing?

You say bones are showing where the break is? Do you mean actually coming out through the skin? If so there is a VERY high risk of infection with a break like that, you need to get the little guy to a vet sooner than Friday. The risk is that the exposed bone becomes exposed to bacteria and debris so needs to be cleaned by the vet before the bones can be stabilized. Antibiotics are also usually given with this type of injury. Do you know specifically how the break occurred? Are there any other signs of injury? Many vet services can direct you to an emergency clinic, which can be costly but are open 24hrs. I would recommend at least calling a clinic like that to get advice. Feel free to PM me if you have questions. Good luck!