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