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