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