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