That's just the way it is. "Like dead fish on a pier" is the best description of it's taste that I've found in years. Sadly, there is no way to disguise the taste and still retain certain benefits. Some people are tempted to add sugar to it, or add it to their protein shakes etc.
Depending on your purpose, adding it to your protein shake, might help to disguise the taste somewhat, but it will negate many of the benefits for which most bodybuilders consume arginine to begin with, and the negatives associates with consuming it that way.... far outweighs any benefits to be had without a suitable accompanying delivery system.