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