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