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