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