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