Contact your station mgr in CVG. He/she should have a commuter badge form that they will sign stating you are an employee for xyz airline. Take this form to the airport id office... it's in a building outside the terminals as you drive toward Term 1, look on the right side for a grey or white building, there will be a door with a green sign on it. This is the office. They will have you fill out some paperwork, take a pic, and pay $50 for a id that is good for 2 years.
Good luck with the commute.
PS: The buses arrive every 5-10 minutes depending on time of day. They stop at Term 1, 2, and 3. Not sure which Term you will be using, but plan on 12-15 min. from parking lot to Term 3. Shorter if you are going to 1 or 2.