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