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