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