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