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