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