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