Honestly just treat the Xenos like Blacks in the 50's, instead of Nigger, Use Ligger or Furball, but don't just say like DIE LIGGER DIE, be like "Hello there Ligger, Hows the work coming along? I better see all those monkies intact in that pen, else you'll be sorry", Also do what most actual people with Racial prejudice do, for example I'm uncomfortable with all of the MP's in my area being minorities, so when you have a Xeno head of staff just act uncomfortable