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