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