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