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