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