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