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