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