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