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