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