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