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