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