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