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