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