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