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