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