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