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