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