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