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