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