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