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