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