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