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