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