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