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