Varnish and Supervisord need to be installed first.
Install Autom8n but it is not free.
Follow the docs here: Install Varnish 4.1.9
Follow the docs here: Install Supervisord 3.3.3
yum install supervisord
run the install.sh script as root. (NOTE: Cpanel plugins can only be installed by root user)
./install.sh
In the Advanced group of Cpanel User Menu, An Icon called Varnish Cache is now available.
Just enable for whichever directory you want to use varnish with.
NOTE: the varnish.vcl file MUST be in a subdirectory immediately under doc root <doc root>/var/varnish.vcl or the default varnish.vcl from /etc/default.vcl will be used negating any effects Varnish will have on your application.