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