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