You've found the ideal construction executive job seeker! The bad news is that after showing him your non-compete agreement on his first day, he feels blindsided and is refusing to sign. He's upset and you're about to lose a great construction executive job seeker. What do you do?

The issue of non-competes should always be handled throughout the recruiting process -- not when a new employee is on the job and filling out paperwork.
You'll need to have a heart-to-heart with the new employee. He feels blindsided, so apologize and let him know that this was an oversight, not a ploy. Let him know that you understand his concerns, and make sure he sees your perspective.
Provide him with your reasons for providing the non-compete and explain the intended spirit of the document. You'll need to determine quickly if you are prepared to hire him without having him sign the agreement. This could set a dangerous precedent, or you may feel that it's not a big issue.