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