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