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