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)(15,16)(17,23)(18,22)(19,24)(20,21)(25,27)(26,28) involution — undirected(5,7,8,12)(6,9,10,11)(13,15)(14,20)(16,22)(17,19)(18,21)(23,28)(24,27)(25,26)(1,2,3,4)(6,10)(7,12)(13,16,26,23,18,20,19,27)(14,21,28,25,22,15,24,17)(6,10)(9,11)(14,22)(16,20)(23,27)(24,28) involution — undirected(13,17,19,15,18,25,26,21)(14,23,24,16,22,27,28,20)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.