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)(11,20)(12,13)(14,24)(15,17)(16,21)(18,23)(19,22)(25,26,32,30)(27,36,38,33)(28,34,29,39)(31,35,37,40)(1,2,5,4)(3,6,8,7)(9,11,15,21)(10,16,17,20)(12,22,23,14)(13,24,18,19)(25,27,32,38)(26,33,30,36)(28,37,29,31)(34,35,39,40)(1,3)(2,6)(4,7)(5,8)(10,17)(11,21)(12,23)(19,24)(25,28,32,29)(26,34,30,39)(27,37,38,31)(33,35,36,40)(1,3,5,8)(2,6,4,7)(9,12)(10,18)(11,22)(13,17)(14,21)(15,23)(16,19)(20,24)(25,29,32,28)(26,34,30,39)(27,31,38,37)(33,35,36,40)(1,3)(2,7)(4,6)(5,8)(9,13,15,18)(10,12,17,23)(11,19,21,24)(14,20,22,16)(25,30,32,26)(27,36,38,33)(28,39,29,34)(31,35,37,40)(1,4,5,2)(3,7,8,6)(9,14,15,22)(10,19,17,24)(11,12,21,23)(13,20,18,16)(25,31)(26,35)(27,28)(29,38)(30,40)(32,37)(33,39)(34,36)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.