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