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