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