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)(11,19)(12,17)(13,21)(14,15)(16,20)(18,23)(22,24)(25,26,30,32)(27,33,34,28)(29,31,37,38)(35,39,40,36)(1,2,4,6)(3,5,8,7)(10,15)(11,20)(17,24)(18,21)(25,26)(27,33)(28,34)(29,31)(30,32)(35,39)(36,40)(37,38)(1,2)(3,5)(4,6)(7,8)(10,15)(11,20)(12,22)(13,23)(27,34)(28,33)(29,37)(31,38) involution — undirected(1,3,4,8)(2,5,6,7)(9,11)(10,16)(12,18)(13,17)(14,20)(15,19)(21,22)(23,24)(25,27,30,34)(26,28,32,33)(29,35,37,40)(31,36,38,39)(9,12)(10,17)(11,21)(13,19)(14,22)(15,24)(16,23)(18,20)(25,28)(26,27)(29,36)(30,33)(31,35)(32,34)(37,39)(38,40) involution — undirected(9,13,14,23)(10,18,15,21)(11,17,20,24)(12,19,22,16)(25,29)(26,31)(27,35)(28,36)(30,37)(32,38)(33,39)(34,40)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.