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