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