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