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