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