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