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