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