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