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