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