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