Here's the secret
Show them proof!
Keep an up-to-date deal sheet – instead of a resume – on your PC at work which you can share with recruiters when they call. Your IT department won’t accidentally find it and automatically assume you’re looking for a new job.
Employers care 1st about who you’ve sold – 2nd how much you’ve sold – and 3rd is your rolodex useful to them. While you may not want to have a resume in circulation with contingency recruiters, a deal sheet can only help you.
Now, this advice isn't just for 'sales' types. Think about what proof you have that you're dong a great job and have it handy when the call comes in.