You’ve identified an executive who would make a great mentor. Now your challenge is to build a relationship with that person. Whatever you do, don’t come out and ask, “Will you be my mentor?” That makes it easy for busy folks to say no.
Instead, ask for advice on an issue you’re facing. Then assess the feedback. If you like what you hear, say, “That really helps. Can I come to you again?” Let the relationship evolve naturally.