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