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