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