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