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