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