1- Login into facebook if you are not already logged in.
2- Now go to the search bar at the topmost center part of the facebook header which you use to search for friends on facebook using their emails,username etc.
3- Now hit enter and wait for the results to appear and the process to complete. Now you would see a green buttton at the end of the search results labelled as “Enable Graph search”. Click on this button and wait for the page to reload and complete the process.
Here you go now your facebook should have got the graph search enabled along with its new look.