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)(11,14)(12,17)(13,16)(15,20)(18,22)(19,24)(21,23)(25,26)(27,34)(28,32)(29,31)(30,33)(35,40)(36,39)(37,38)(3,7)(5,8)(9,10)(11,14)(12,15)(13,16)(17,20)(18,22)(19,23)(21,24)(25,27,30,29)(26,31,33,34)(28,35,36,37)(32,38,39,40)(1,2)(3,5)(4,6)(7,8)(10,11)(15,17)(16,18)(23,24)(28,36)(32,39)(35,37)(38,40) involution — undirected(1,3,4,7)(2,5,6,8)(9,11,14,10)(12,17,20,15)(13,16,22,18)(19,23,21,24)(25,28)(26,32)(27,35)(29,37)(30,36)(31,38)(33,39)(34,40)(1,2)(3,5)(4,6)(7,8)(9,12)(10,15)(11,17)(13,21)(14,20)(16,24)(18,23)(19,22)(25,26)(27,31)(28,32)(29,34)(30,33)(35,38)(36,39)(37,40) involution — undirected(9,13)(10,16)(11,18)(12,19)(14,22)(15,23)(17,24)(20,21)(25,29,30,27)(26,31,33,34)(28,35,36,37)(32,40,39,38)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.