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