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