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