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