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