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