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