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