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