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