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