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