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