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