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