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