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