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