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