Beth, children have a way of bringing our baggage out and forcing us to deal with it. I guess I would start with examining your beliefs. Is kissing on the lips something that you believe should only be a romantic gesture between husband and wife, or do you believe that it can be a loving gesture between parent/child, siblings, engaged couples, or friends? If it is the former, then this is where you lay the foundation for teaching her your beliefs about chastity by telling her that you love her very much and you want to allow her to save kisses on the lips for the very special man who will be her husband, so you will kiss her on her cheek, on her head, on her hand, etc, but you'll save her lips for her husband. If it is the latter, then you may have to work to define what kissing means better for her.
Another way to consider the question is do you feel uncomfortable with kissing her on the lips because you feel that it is wrong, or are you uncomfortable of it only because of your own baggage? If it is the latter, your situation is more complicated because you're trying to hold your daughter to a boundary that is a personal but not a moral boundary. You can still address it by talking about personal boundaries, but it's hard for a child to comprehend. This does leave open the possibility that your personal boundary could change someday. Either way, this is an opportunity for you to seek healing from your past.