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