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)(27,31)(28,39)(29,33)(30,35)(32,36)(34,38)(37,45)(40,52)(41,44)(42,48)(43,49)(46,50)(47,51)(53,56)(54,55)(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)(28,36,41,51)(29,37,43,42)(32,44,47,39)(33,45,49,48)(40,50,54,53)(46,55,56,52)(1,4,5,2)(3,7,8,6)(9,12)(10,15)(11,17)(13,20)(14,21)(16,24)(18,19)(22,23)(25,28,38,51,30,41,27,36)(26,32,31,44,35,47,34,39)(29,40,42,53,43,54,37,50)(33,46,45,55,49,56,48,52)(3,8)(6,7)(12,20)(15,24)(17,19)(21,23)(25,29)(26,33)(27,37)(28,40)(30,43)(31,45)(32,46)(34,48)(35,49)(36,50)(38,42)(39,52)(41,54)(44,55)(47,56)(51,53) involution — undirected(10,16)(11,18)(15,24)(17,19)(25,27,30,38)(26,31,35,34)(28,36,41,51)(29,42,43,37)(32,44,47,39)(33,48,49,45)(40,53,54,50)(46,52,56,55)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.