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