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