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