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