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