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