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