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