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