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