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