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