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