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