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