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