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