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