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