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