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