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