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