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