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