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