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