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