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