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