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