When dealing with employees who may be viewing the world from a pedestal, there are a number of factors to consider before taking action. In the first place, are you absolutely certain that the issue is his arrogance, rather than jealousy by the other employees? You have a successful outside salesperson, and it is possible that the employees who are not doing as well may regard his confidence and self-assurance as unbridled arrogance.
If you determine that you are dealing with a certifiably arrogant person, you have some fundamental issues to consider. For example, since he is successfully generating revenue for the company, you may sense some reluctance to take any action. And further, it is possible that his arrogance plays an important role in his high degree of sales effectiveness. However, remember that he has also shown a high degree of effectiveness in alienating just about all of your employees, and it is safe to predict that his working relationship with them is only going to deteriorate unless some action is taken.
One step is to meet with him and suggest that he do some work in "internal sales." In a word, he needs to market himself better with the other employees. In addition, although you cannot change his personality, you can certainly have an impact on some of his behaviors. Give him specific examples actions that have caused the employees to bristle, and then give him some coaching as to more appropriate actions to take. You can also have him meet with some of your key employees to discuss their working relationship and try to jointly develop a strategy to work more productively together.
Since change can be accelerated when people have some incentive for doing so, show him the specific ways that he can be even more successful if he has the support of his fellow employees. After all, the best businesses today have a strong sense of teamwork, unity, and shared purpose. If this is what you want for your business, then this employee needs to understand that you mean business. | 
