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