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