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