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