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