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