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)(13,14,18,16)(15,17,20,19)(23,25)(27,28)(6,7)(10,11)(13,15)(14,19)(16,17)(18,20)(21,22,26,24)(23,28,25,27)(8,12)(10,11)(15,20)(17,19)(21,23,26,25)(22,27,24,28)(1,2)(3,4)(5,7,9,6)(8,10,12,11)(13,16,18,14)(15,19,20,17)(21,24,26,22)(23,28,25,27)(5,8,9,12)(6,10,7,11)(13,17,18,19)(14,15,16,20)(21,25,26,23)(22,28,24,27)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.