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)(15,19)(16,21)(17,20)(18,23)(22,25)(24,27)(26,28) involution — undirected(1,2)(3,4)(6,9)(7,11)(13,15,18,24)(14,19,23,27)(16,17,26,25)(20,28,22,21)(2,4)(14,20)(15,24)(17,25)(19,21)(22,23)(27,28) involution — undirected(6,9)(10,12)(13,16,18,26)(14,21,23,28)(15,25,24,17)(19,22,27,20)(2,4)(5,7,8,11)(6,10,9,12)(15,24)(16,26)(19,27)(21,28)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.