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