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