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