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