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