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