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