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