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