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