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