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