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