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