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