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