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