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