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