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