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