how to set up CloudFront using my domain

I get my original domain, and using S3 via CloudFront. I want to know how to setup using my domain via CloudFront.

I already upload my contents to S3 and not public bucket, and setup CloudFront. I can access via CloudFront to S3 bucket, but currently using auto generate url from CloudFront. So I want to know how to setup my original domain using CloudFront.

Thanks