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