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