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