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