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