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