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