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