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