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