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