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