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