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