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