CATS allows you to hide the '.catsone.com' from the URL of your careers page. This process is called domain masking.
To do this, you'll need to login to the DNS provider for your website (GoDaddy, Network Solutions, etc.). Using the domain management tools, create a CNAME record pointing a new subdomain (e.g.: jobs.yourname.com) to the following hostname: companyID.catsone.com (being sure to replace companyID with the company ID that you use to log in to CATS).
If you are unaware of how to do this, please contact the FAQ or support for your domain provider; it's a fairly common task and there should be documentation on their website.
Once complete, add your newly created record to CATS in the Portal > Domain Masking location.