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