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