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