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