She may not take you back, but she might. If you cheated, make your life and what you do/where you are an open book. Answer any question she has. If you say you'll be home at 10, be there by 10. The only way to make her feel secure and learn to trust again is to do exactly what you say you will do.
Be thoughtful. Bring home her favorite meal, help out around the house, clean up after yourself. Take her out. Let her be sad or upset if she needs to be, but make it clear that you are really sorry.