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