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