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