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