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