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