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