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