What is the best design to show all users in a site?

In this site, when the logged in user clicks on Client , I need the site to show all clients that are registered. I am using datatables for this, but I am really not fond of the design and how it looks like. Is there any way I could change this and make it more user-friendly ? Also need to add an Add User button somewhere.

What would the best design for such purpose be?