One vertex per element, one color per generator, with an edge from x to x·s.
(9,10)(11,16)(12,17)(13,22)(14,15)(18,19)(20,23)(21,24)(25,26,32,36)(27,37,40,33)(28,31,30,34)(29,39,38,35)(1,2)(3,6)(4,5)(7,8)(9,10)(11,16)(12,13)(14,15)(17,22)(18,24)(19,21)(20,23)(25,27,32,40)(26,33,36,37)(28,38,30,29)(31,39,34,35)(2,5)(6,8)(10,15)(13,17)(16,23)(19,24)(25,28,32,30)(26,34,36,31)(27,38,40,29)(33,35,37,39)(3,7)(6,8)(9,11,14,20)(10,16,15,23)(12,21,22,18)(13,19,17,24)(25,29)(26,35)(27,28)(30,40)(31,33)(32,38)(34,37)(36,39)(1,3)(2,6)(4,7)(5,8)(9,12)(10,17)(11,18)(13,15)(14,22)(16,19)(20,21)(23,24)(25,30,32,28)(26,34,36,31)(27,38,40,29)(33,39,37,35)(1,2)(3,6)(4,5)(7,8)(9,13,14,17)(10,12,15,22)(11,19,20,24)(16,21,23,18)(25,31,32,34)(26,28,36,30)(27,39,40,35)(29,33,38,37)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.