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