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