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