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