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