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