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