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