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