One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,11)(8,12)(9,10)(13,14,18,16)(15,23,25,20)(17,21,22,19)(24,27,28,26)(2,4)(6,10)(11,12)(13,15,18,25)(14,20,16,23)(17,24,22,28)(19,27,21,26)(5,7,9,8)(6,11,10,12)(13,16,19,17,18,14,21,22)(15,24,26,23,25,28,27,20)(1,2,3,4)(13,17,19,14,18,22,21,16)(15,20,26,24,25,23,27,28)(5,8,9,7)(6,11,10,12)(14,16)(17,22)(20,23)(24,28)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.