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