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