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