Maybe. Requiring an employee to shave his beard can end up in discrimination, because certain races, such as African Americans, have disorders that make it more burdensome to shave. For example, men who have Pseudofollicullitis Barbae, a skin disorder that is specific to African Americans, experience pain when shaving. Several individuals have successfully challenged companies that have required them to shave their beards.
However, if you do not have a skin condition as a result of your race and just prefer to have facial hair for personal and/or appearance reasons, you may not be able to challenge this requirement, as it is not discriminatory as applied to you.