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