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