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