Having Amazon S3 and CloudFront enabled for the S3 content (actually serve static website). Any updates to the bucket takes randomly from 15 minutes to 1 day. What can I do with settings to make this faster?
After you update the object in S3 you have to remove the object from the CloudFront cache so that CloudFront will go back to S3 to get the new version. This is called "cache invalidation". Since you aren't doing this, CloudFront isn't going back to check for a new version until the cache expires, which is why it is taking so long for the new version to show up.
You can read about invalidating CloudFront cache here.