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