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