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