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