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