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