ProxyPassReverse / http://localhost:631
Press CTRL+X to exit and save.
It should look like this:
<VirtualHost *:80>
ServerName cups
ServerAlias cups.sabatech.com
ProxyPass / http://localhost:631/
ProxyPassReverse / http://localhost:631
DocumentRoot /var/hda/web-apps/cups/html
<Directory "/var/hda/web-apps/cups/html">
Options Indexes FollowSymLinks +ExecCGI
AddHandler fcgid-script .fcg
AllowOverride AuthConfig
Order allow,deny
Allow from all
</Directory>
ErrorLog /var/hda/web-apps/cups/logs/error_log
CustomLog /var/hda/web-apps/cups/logs/access_log combined env=!dontlog
</VirtualHost>
Your Done.