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