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