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