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