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