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