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