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