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