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