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