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