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