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