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