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)(11,16)(12,15)(13,17)(14,18)(19,23)(20,21)(22,24)(25,26,30,29)(27,34,37,31)(28,33,38,32)(35,39,36,40)(1,3,5,8)(2,6,4,7)(9,11)(10,14)(12,19)(13,18)(15,22)(16,17)(20,23)(21,24)(25,27,30,37)(26,31,29,34)(28,36,38,35)(32,40,33,39)(11,18)(14,16)(19,24)(22,23)(25,28,30,38)(26,32,29,33)(27,35,37,36)(31,39,34,40)(1,2,5,4)(3,6,8,7)(9,12)(10,15)(11,19)(13,21)(14,22)(16,23)(17,20)(18,24)(25,28)(26,33)(27,36)(29,32)(30,38)(31,39)(34,40)(35,37)(1,4,5,2)(3,7,8,6)(9,10)(11,16)(12,20)(13,17)(14,18)(15,21)(19,22)(23,24)(25,27)(26,31)(28,35)(29,34)(30,37)(32,39)(33,40)(36,38)(9,11)(10,16)(12,19)(13,18)(14,17)(15,23)(20,22)(21,24)(25,29,30,26)(27,34,37,31)(28,32,38,33)(35,39,36,40)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.