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