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