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