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