One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,11)(8,12)(9,10)(13,14,19,15)(16,18,22,23)(17,24,26,25)(20,28,21,27)(2,4)(6,10)(11,12)(13,15,19,14)(16,23,22,18)(17,25,26,24)(20,27,21,28)(5,7,9,8)(6,11,10,12)(13,16,18,15,19,22,23,14)(17,25,27,20,26,24,28,21)(1,2,3,4)(13,17,23,28,19,26,18,27)(14,20,22,25,15,21,16,24)(5,8,9,7)(6,11,10,12)(17,26)(20,21)(24,25)(27,28)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.