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