Want to reaudit your site with the exact same settings as before? Go to a completed crawl and click the big green button Start a New Audit. A drop-down menu will appear with two options "Start and configure audit" and "Start with current configuration".
If you are happy with the current setting and just want to go ahead and re-audit then click on the "Start with current configuration" option. This will crawl with all the same settings as you entered for the previous crawl.
If you want to check your settings and/or make amendments, then select the "Start and configure audit" option - this will still load in all the settings used in your previous crawl but will also give you the option to change any settings before starting the new audit.