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