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