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