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