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