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