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