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