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