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)(13,14,18,20)(15,21,25,28)(16,19,23,27)(17,26,24,22)(1,2,3,4)(13,15)(14,19)(16,24)(17,23)(18,25)(20,27)(21,26)(22,28)(5,7,8,11)(6,10,9,12)(14,20)(15,23)(16,25)(17,24)(19,21)(27,28)(13,16,18,23)(14,21,20,28)(15,24,25,17)(19,26,27,22)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.