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