One vertex per element, one color per generator, with an edge from x to x·s.
(9,10)(11,17)(12,15)(13,16)(14,19)(18,23)(20,22)(21,24)(25,26,30,35,29,34,43,32)(27,36,39,45,38,31,44,47)(28,40,42,48,41,33,49,50)(37,46,53,56,52,51,54,55)(1,2,4,5)(3,7,8,6)(9,11)(10,14)(12,18)(13,19)(15,21)(16,17)(20,24)(22,23)(25,27)(26,31)(28,37)(29,38)(30,39)(32,45)(33,46)(34,36)(35,47)(40,51)(41,52)(42,53)(43,44)(48,55)(49,54)(50,56)(2,5)(6,7)(9,12,13,20)(10,15,16,22)(11,18,19,24)(14,21,17,23)(26,32)(30,43)(31,45)(33,48)(34,35)(36,47)(39,44)(40,50)(42,49)(46,55)(51,56)(53,54)(10,16)(14,17)(15,22)(21,23)(25,28,29,41)(26,33,34,40)(27,37,38,52)(30,42,43,49)(31,46,36,51)(32,48,35,50)(39,53,44,54)(45,55,47,56)(1,3,4,8)(2,6,5,7)(11,19)(14,17)(18,24)(21,23)(27,38)(28,41)(31,36)(33,40)(39,44)(42,49)(45,47)(48,50)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.