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