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