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