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