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