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