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