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