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