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