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