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