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