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