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