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