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