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