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