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