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