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