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