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