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