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