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