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