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