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