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