Can you? Yes. Should you? Well, that depends on the individual. According to the American Sleep Apnea Association (ASAA):

The ASAA does not believe that individuals who are excessively sleepy because of a diagnosed but untreated sleep disorder should drive; they are a risk to themselves and others. However, there is no indication that an adequately treated sleep disorder increases anyone's risk for a fall-asleep crash. In fact, recent research indicates that treatment of sleep apnea with a CPAP (Continuous Positive Airway Pressure) machine reduces the risk of a fall-asleep crash to that found in the general population.

So, sounds like if you've been formally diagnosed and treatment is going well, driving shouldn't be a problem. However, if it's undiagnosed or treatment isn't working, maybe one should take a break from driving for a while. Ultimately, if you're asking on behalf of yourself, I would recommend speaking with your doctor to assess your own personal situation.