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