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