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