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