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