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