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