Depends... Apple laptops are not really intended for strenuous work, which graphics design COULD be.
If we're talking probably 30-45 minutes/day or less, then maybe, but much more than that and you will likely bump into some issues with the thermal regulation systems.
If you're going to be doing rather large projects, you probably would be a whole lot happier with an iMac or Mac Pro. For light work, which is maybe just kind of tinkering with ideas that you will later do in earnest on a more capable machine, then you are probably fine.
Should you choose to disregard the above advise, make VERY sure that you are RELIGIOUS about taking off the bottom cover and blowing some compressed air into the fan(s) to keep the blades clear of any dust and other debris. I work as an Apple repair tech, and you would be amazed at some of the crap I find in people's systems. Some people are truly disgusting creatures if their computers are any indication.