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