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