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