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