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