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