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