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