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