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